Xiong Jie, Peng Yin-Hui, Lin Jia-Yi, Cen Yu-Jie, Yang Xiao-Bao, Zhao Yu-Jun
Department of Physics, South China University of Technology, Guangzhou 510640, China.
Materials (Basel). 2023 Aug 7;16(15):5496. doi: 10.3390/ma16155496.
MnSbTe has a similar structure to an emerging material, MnBiTe. According to earlier theoretical studies, the formation energy of Mn antisite defects in MnSbTe is negative, suggesting its inherent instability. This is clearly in contrast to the successful synthesis of experimental samples of MnSbTe. Here, the growth environment of MnSbTe and the intrinsic defects are correspondingly investigated. We find that the Mn antisite defect is the most stable defect in the system, and a Mn-rich growth environment favors its formation. The thermodynamic equilibrium concentrations of the Mn antisite defects could be as high as 15% under Mn-poor conditions and 31% under Mn-rich conditions. It is also found that Mn antisite defects prefer a uniform distribution. In addition, the Mn antisite defects can modulate the interlayer magnetic coupling in MnSbTe, leading to a transition from the ideal antiferromagnetic ground state to a ferromagnetic state. The ferromagnetic coupling effect can be further enhanced by controlling the defect concentration.
MnSbTe与一种新兴材料MnBiTe具有相似的结构。根据早期的理论研究，MnSbTe中Mn反位缺陷的形成能为负，这表明其固有不稳定性。这与MnSbTe实验样品的成功合成明显矛盾。在此，对MnSbTe的生长环境和固有缺陷进行了相应研究。我们发现Mn反位缺陷是该体系中最稳定的缺陷，富Mn的生长环境有利于其形成。在贫Mn条件下，Mn反位缺陷的热力学平衡浓度可达15%，而在富Mn条件下可达31%。还发现Mn反位缺陷倾向于均匀分布。此外，Mn反位缺陷可调节MnSbTe中的层间磁耦合，导致从理想的反铁磁基态转变为铁磁态。通过控制缺陷浓度可进一步增强铁磁耦合效应。
